text: The gene encoding the human serotonin transporter (5-HTT) has been isolated and characterized. The human 5-HTT gene is composed of 14 exons spanning ∼ 31 kb. The sequence of all exons including adjacent intronic sequences and a tandem repeat DNA polymorphism (VNTR) has been determined and deposited in the EMBL/GenBank data base with the accession numbers X76753 to X76762. The characterization of 5-HTT gene will aid to advance molecular pharmacologic studies of 5-HT uptake regulation and facilitate investigations of its role in psychiatric disorders.